First, get your pan ready. Line an 8x8-inch pan with parchment paper, leaving some overhang on the sides.
Step 1: Build the Crust. In a bowl, combine your chocolate cookie crumbs and melted butter. Stir it together until it looks like wet sand. Pour this mixture into your prepared pan and press it down firmly and evenly. Pop this crust into the refrigerator while you make the filling.
Step 2: Whip up the Cheesecake Filling. In a medium bowl, beat your softened cream cheese, sugar, and vanilla extract with an electric mixer (or by hand) until it's completely smooth and there are no lumps. Gently fold in 3/4 cup of the mini chocolate chips.
Step 3: Spread the Cheesecake Filling. Carefully spoon and spread the smooth cheesecake filling over the chilled crust in your pan. Get it as even as you can. Back into the refrigerator it goes for at least 3-4 hours to firm up.
Step 4: Make the Glorious Ganache. When your cheesecake layer is almost firm, heat the heavy cream in a small saucepan over medium heat until it just begins to simmer around the edges. Remove from heat, pour in the semi-sweet chocolate chips, and let sit for about 5 minutes. Gently whisk or stir until completely smooth, glossy, and pourable.
Step 5: Top it Off! Pour the warm (but not hot!) ganache evenly over the chilled cheesecake layer in the pan. Gently spread it right to the edges if needed. While the ganache is still soft, sprinkle the remaining 1/4 cup of mini chocolate chips over the top. Now, back into the refrigerator for another 1-2 hours to let that ganache set up.
Step 6: Slice and Serve. Use the parchment paper overhang to carefully lift the entire cheesecake slab out of the pan and onto a cutting board. For the cleanest slices, use a sharp knife and wipe it clean with a warm, damp cloth between cuts. Slice into bars of your desired size. Serve them chilled.